Technical Field
The present invention relates to a bus bar holding member used to connect a plurality of battery terminals with one another, as well as to a battery pack.
Related Art
A technique disclosed in JP 2010-282811A has been known with respect to a battery pack. The battery pack is configured to connect a plurality of cylindrical batteries in parallel or in series and includes: battery array groups, each having an array of a plurality of cylindrical batteries; bus bars arranged to electrically connect the plurality of batteries and the battery array groups; and an insulating outer shell member configured to hold the bus bars and prevent a short circuit between the bus bars. In this battery pack, the insulating outer shell member is provided as a separate member from the bus bars and is assembled with the bus bars.
A battery pack using a metal member-incorporating based plate has been known as another prior art technique (JP 2010-218797A). The metal member-incorporating base plate has a plurality of bus bars as insert members embedded in a resin material during injection molding. This provides insulation and facilitates assembling.
The technique disclosed in JP 2010-282811A, however, has the following problems. The insulating outer shell member is used to provide insulation between the bus bars and prevent a short circuit between the bus bar and the outside. This insulating outer shell member is provided as a separate member from the bus bars and accordingly needs complicated assembling. The insulating outer shell member has ribs in a cylindrical shape to increase the insulating distance. This undesirably increases the dimension of the insulating outer shell member in the thickness direction.
The technique disclosed in JP 2010-218797A, on the other hand, has the following problem. The metal (bus bars) and the resin (resin member) have significantly different thermal contractions during injection molding. A large stress is accordingly generated in an area which is between the bus bars and is made of only the resin material during cooling and solidification after injection molding. The metal member-incorporating base plate is thus undesirably likely to have bending deformation from this area as the starting point.